Pneumatic spring.



B. BBLL. PNBUMATIG SPRING.

APPLICATION FILED AUG.12,199.

Patented Oct. 4, 1910.

2 SHBBTS-SHBBT 1.

INVENTOR jTEssEs B. BELL. PNEUMATIC SPRING.

APPLICATION FILED AUG.12, 1909.

Patented. Oct'. 4, 1910.

2 SHEETS-SHEET 2.

v.l .M A. 5 af 5 5 w 4 M ./U

WITN SSES BENJAMIN BELL; `or. PHILADELPHIA, PENNSYLVANIA.

vPNEUIXIATIC SEEING.

Specification of Letters Patent.

l raeenfedroet. 4, 1910.

Application filed August 12, 1909. Serial VNo. 512,569.

To all whom ttmay concern:

Be it known that I,A BENJAMIN BELL, a subject'of the Kingof Great Britain, residing at Philadelphia, in the county of Philadelphia and Stateof Pennsylvania,

have invented certain new and useful Improvements in Pneumatic Springs, of which the following is a specification. 1

The object of this invention is to provide a novel, simple and eliicient pneumatic spring which may be adapted for use in connection with vehicles and in various other connections.

The invention consists in the novel construction and combinations of parts which will be hereinafterfully described and par y ticularly claimed.

In the drawings Figure 1 isa vertical section of one form O15-embodiment ofmy invention. IFig.A 2 is a horizontal section thereof on line'2-2 of Fi 1. Fig. 3 is a development of a port-ion o thetubular dias i phragm,.partly brokenaway and shown in section. Fig.. 4 isan edge View of the portion of the. diaphragm'shownin Fig. 3. Fig. 5 is a vertical sectionof another form l of embodiment ofv my invention. Fig. 6

is a vertical section of anotherform of embodiment'of my invention. A

f Refering' to Figs. 1,23 and 4: 3 and'4 designate upper and lower members respetetively, and 5 a flexible diaphragm interposed between the members 3 and 4. -The upper member 3 `comprises a tubular portion 6, the upper end of which is closed by ahead 7 which maybe formed on vor secured to the tubular portion 6. The bottom of the tubular portion 6 isprovided with an outwardlyextending lflange 8, and'secured tov the, flange' 8 -bymeans of bolts 9 is a Harige 10 which extends houtwardly from a tubular portion' 11 which forms in effect a part of the up er' ymember 3 and a continuation' ofthe tubu Yar portion 6 thereof. Ther` lower portion 11 ofthe member `3'is flared outwardly, as atv 12, as shown, fora purposehereinafter described. The lower member 4.comprises a 1 tubular prtion 13 Ithelow'er end of which provided with v,an inwardlyfextending ange 15 and secured to the flange 15 by means of' is closed by a head 14 which maybe formed on or secured to the tubular 'portion The-upper-endof the lower member 4 is bolts 16 is a ring 17. .f

arranged tube 18 which may be formedon or secured to the end head 7; and extending trally-arranged rod 19 which may be formed on or secured'to the end head 14. The upper end of the rod 19 terminates below the that the tube 18 and rod 19 fo fm a suitable guiding device for the upper andl lower members 3 and 4, lwhereby slid members may be moved toward and fro n each other and Vheld in proper relation wi th respect to each other.A j f The. end head 7.01 the uppermember 3 is provided with an exteriorly-'airanged ring 20, and the end head 14 of the lower member 4 is provided with an-'exteriolly-arranged ring 21, which rings 20 and 21 fc rm a means whereby the members 3 and 4 :respectively may be attached to any suitable devices in connection with which it is desired to use the spring. The upper ring 20 is formed on a rod or st eni 22 which is scre\\'-t-hreaded lupwardly from the end head '14 of the lower` 'member 4 and into the tube. 18, is -a centop of the tube 18, and it will thusbe seen i and screwed into the end head 7 of the upthrough the end head 14 df the lower member 4. The rod 19 vis screw-threaded and screwed into the end head 14, and a suitable jam nut 23 is providedbetwee'i which and the end head 14 packing 24 is f rranged.

-`The lower member 4 extends into the upper member 3, as shown, and the interior diameter of the upper and outer member 3 isgreater thanthe'exterior diameter of the 'lower and inner member 4, thus providing a space between the two members 3 and 4 in whiehthe diaphragm 5 is arranged.

.The diaphragm 5 ,is made.. tubular in form and one end .thereof is extended between the flanges 8 vand 10 entirely around the upper member 3, and is firmly secured therebetween by the bolts 9 ina manner to form an air-tight joint; and the other endof the tubular. diaphragm 5 .is extended between the Han-ge 15y and ring 17, eutirely around the member 4, and is firmly' secured therebetween by the bolts 16 in a manner to form an air-tight joint. The end portion of the tubular diaphragm 5 secured to the inner or lower member 4 is brought upwardly within the end portion of the diaphragm secured to theI outer orup er member 3, bending the 'diaphragm so t at 'it will appear substantially U-shaped in cross section, as shown in Fig. 1, extending across the space between thel members 3 and 4 and being in engagement with the inner wall of the upper member 3 below the flange 10 and with the outer wall of the lower member 4 below the flange 15.

The 'upper and lower members 3 and 4 re- I' specti'if'ely and the diaphragm 5 lform walls of an inclosed air-chamber into which air under pressure lmay be ,introduced through an opening 26 in the upper member 3,which 'opening 26 i`s`closed by a suitable 'screwthreaded 4 remvable cap 27.

From the foregoing description .it will be seen that after the compressed air has been introduced to the chamber 25 the-members 3 and 4`may be moved toward each other against the spring or' cushioning .actionof the air contained within the chamber. It will also be seen that, as the members 3 and 4 are moved away from each'ot-her by the air press-ure within the chamber the ring formed by that portion of the diaphragm .'3v extending across the space between the ktwo members'will increase in diameter, due

to the outward flaring portion 12 of the outer vmember 3, thereby increasing the area of au' pressure acting agalnst the members 3 and 4 transversely of their direction of .movement to-move said members apart and compensating by such increased area forV the decrease in air pressure per square inch due to the movement of the members away from each other, so that any desired resultant pressure may be maintained against .the two members 3 and 4 in the direction of their movement away from each other, irrespective of the relative positions of said members. l

The angle of the flaring portion 12 may p be changed so that the area of pressure acting against the members 3 and 4 will in'- 1 crease with themovement of lthe members 3 and 4 away from each other, and decrease with the movement 'of the members 3 and'4 3 forms an important part of my invention,

forv by its use and variation any desired load mayI be carried by the upper member, supported by the lower member,.and said load may be moved downwardly against the cushioning or spring action of the air pressure within the chamber,y 25 and returned.

to normal position by the pressure within the chamber 25, the angle of thev flaring porevmsaa air pressure per square inch as the members 3 and 4 are moved in a direction away from each other.

The tubular diaphragm is preferablv -made of rubber, and it is expanslble in the directionof its width, so that when one end portionof the diaphragm is in engagement with the exterior wall of the inner member 4 the other end portion of the diaphragm may expandrinto engagement with theinte-4 rior wall of the outer member 3; and means are provided to prevent the diaphragm from expanding in the direction of its length under the air pressure within the chamber 25, to prevent the diaphragm from being blown out through the space between the members 3 and 4. As a suitable means to )revent the tubular diatphrafrm from expan ing in the direction o its Tength as just mentioned, I provide as eries of -parallel threads 28 which extend longitudinally of or ilnthe direction ofthe length of the tubular diaphragm, and which are embedded in the rubber of the diaphragm as shown in Figs. 3 and 4.

The construction shown in Fig. 5 is identical with the construction shown in Figs. 1 and 2, excepting that the wall of the lower portion 11 of the upper member 3 is made parallel with the tubular portion 13 of the lower member 4. It will thus be seen that in the construction shown in Fig. 5 the area of pressure against the members 3 and 4 transversely o? their directions of movement will remain constant irrespective of the relative positions of said members, thus eliminating the compensating feature )resent in the construction shown 1n Fig. 1 ue to the outwardly Haring portion 12 shown in Fig. 1 and previously .described herein.

The construction shown in Fig. 6 is designed to act as a vacuum chamber, and to act the reverse of the construction shown in Fig. 1; that is to say, the construction shown in Fig. l is adapted to support a load by movin@ the members 3 and 4 toward each other, and the construction shown in Fig. (i is adapted to support a. load in suspension by moving .the'members A3 and 4 in direc tions away from each other. The construetion shown in Fig. (3 includes the upper member 3 and the lower member '4, and is identicall with the construction shown in Fig. l, with the followin exceptions The bottom portion of the tu ular portion 6* is ared outwardly, as at 30, and the bottom ofthe outwardly fiarin portion 30 is provided with an outwar ly-extending flange 31. Secured to the flange 31 by means of bolts 32 is a ring 33. The upper end of the lower member 4 is provided with an inwardly extending fiange 34, and secured to tlie'flange'34 vby' means of bolts .36 which extends inwardly portion 37- which forms in effect' a part ofi 35 is a flange from av tubular which is extended between the anges 34 and 36 entirelyaround the lower member 4 and is i'irmly secured therebetween by the joint.

33 entirely around the' member' 3 and fis lirmly Secured therebetween by the 'bolts-"32 in a manner to form an air-tight joint. The

diaphragm 38 extends across the space beV ltween'the members 3 andl4 similar to the manner in which the diaphragm .v extends across the space between the members 3 and .'4 as shown in Fig. 1, excepting that the diaphragm 38 is'made the reverse of the diaphragin shown in Fig. 1, the parts of the' I phragm 38 engaged with theV walls of'the n members 3 and 4 being exposed to the exa tern'al air, while the similar parts of the diaphragm- 5 shown in Fig'. 1 are exposed to the interior 'of tlie'cliamber l From the yconstruction shown in Fig.- Gv as just described,` it will kbe'seen that after aii has been exhausted -froni the chamber'25a 'formed byftlie .members 3 and 4l and (liaplii'agm 38 to torni a'partial vacuum within the chamber, the members 3 aiid4fniay be moved away from" eachother against the spring or cushioning action of the'. partial ItI will.

vacuum within the chamber 25a.

, also be seen that as the members 3 and 4 a'r'e moved toward eachother' bythe partialv 25, the,A ring. formed by that portionof thediaphragm 38 vacuum within the chamber extending .across the' space between the two 'members will decrease in diameter due to theoutwardflaring portion 30 of the upper A member 3, thereby decreasing the area.' vof the partial vacuum acting upon the menibers' 3 and 4y within the cliamber-Qfbl transversely of the directions of'movement of the members3and 4, and compensating by such decreased area for the decrease of the partial vacuum within the chamber 25a due to the movement of the members toward each other. y The angle of the Haring portion 30 may be changed to meet any v.desired requirev ments. Saving and excepting that in the construction shown inl Fig.v 6 a vacuum chamber 25a is employed and that'in the construction shown in Fig. 1 a compressed air chamber :25 is employed, and that the cushioning actions of tlieinembers 3 and 4 of the construction 'shown in Fig. 6 is di-' i rectly op osite to the cushioning actions of the mein ers 3 and '4 of 'the constructionshown in Fig.. 1, the results of the two 'con- I claimf- Q 1. In a pneumatic spring, two relatively 'movable members forming `walls of an intowardthe interior o'f the chamber;l and a y kflexible diaphragm secured 'to and intervposed "between said members and engaged bolts 35 in a manner to forni an' air-tight i The other end o f the' diapliragm 38' is extended between the flange 311 and ringl n -ith and extending across the space between said 'adjacent walls. '1 i l 2. Inga pneumatic sprin two relatively movable membersforming walls of an inclosed1 chamber and including adjacent wallswhich converge with respect to Aeach other towardthe interior ofthe chamber; and a flexible diaphragm secured to .and interposed between said members and' having a` 4portion Iextendingacross the space between said adjacent walls and portions .con-verging toward eachother from the rst named portion'and'engaged with said adjacent walls.

3..In a pneumatic spring,' two relatively movable ytubular members arran ed one' within the vother and forming Iwal s of an ner memberA and .the inner wall ofvthe outer member converging with respect to each other toward the interior of the chamber; and 'a vflexible diaphragm secured to and interposed between said membersfand engaged' with and extending `across the space between said inner wall and said outer wall.

4. In a pneumatic spring, two relatively movable tubular members arranged one within the` other and forming walls f anin- 'closed chamber,` the outer wall of the inner inemberandrthe inner wall of' the outer 'member Vconverging with. respect Yto each 'other toward 'the interior of the chamber; land alexible diaphragm secured to .and'interposed between'said members and having a portion extending across the space `between said inner wall and said outer wall and portions convergingtoward each other from the I structions shown in Figs. 1. and 6 are subi stantially identical.

jinclosed chambenthe outer wall. oif the in- 'i first named portion and engagedvwith said vinner wall and saidouter wal.

5. In a pneumatic spring, two relatively movable members forming walls of an inclosed chamber and including adjacent walls which converge with respect to each other toward the interior of the chamber; a lexible diaphragm securedy to and interposed between Said members and engaged with and extending across the space between said adjacent walls; and means for guiding said lmembers including atube fixed to one of Asaid members anda rod iixed to the other of said; members and ext-ending into said tube.

"6. In a' pneumatic spring,- two relatively 'movable tubular. members arranged one `withiny the other and forming walls of an .in-

closedchamber, the outer wall of the inner ,member and the inner wall of the outer member converging with respect to each other toward the interior of the chamber; a flexible diaphragm secured to and interposed between said members and engaged with and extending across the space between said inner wall and said outer wall; a centrally-arranged tube ixed to one of said members; and a centrally-arranged rod fixed to the other of said members and extending into said tube.

7 In a pneumatic spring, two relatively movable members arranged one'within the' other and out of Contact with each other and forming walls of `an inclosed chamber; a

flexible diaphragm secured to and interposed between said members; a centrally-arranged tube fixed to one of said members; and a centrally-arranged rod fixed to the other of said members and extending into said tube, said tube being movable within one of said members and said rod being movable within the other' of said members.

`In testimony whereof I aflix my signature in presence of two witnesses.

BENJAMIN BELL. Witnesses:

A. V. GROUPE,

S. I. HARPER. 

